Fire-resistant panel comprising loess and fire-resistant decorative panel using the same

ABSTRACT

The present invention relates to a fire-resistant panel having superior fire resistant properties and a low dimensional variation ratio, and a fire-resistant decorative panel using the same. In detail, the present invention provides a fire-resistant panel comprising a) a substrate of inorganic-fiber-based fabric or non-fabric, or paper; and b) a resin blend containing i) a thermosetting resin selected from a group consisting of phenol resin, phenol modified resin, phenol-urea modified resin, melamine resin, melamine modified resin, melamine-urea resin, urea resin, and urea modified resin; and ii) loess, which is impregnated or coated to the substrate of a), and a fire-resistant decorative panel using the same as a substrate material.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/220,478, filed Aug. 28, 2002, which was a national stage filing under35 U.S.C. 371 of PCT/KR01/02289 filed Dec. 28, 2001, which InternationalApplication was published by the International Bureau in English on Jul.11, 2002 and which claims priority from Korean Application No.2001-0069636 filed Nov. 9, 2001 and Korean Application No. 2000-0085422filed Dec. 29, 2000.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a fire-resistant panel, and moreparticularly, to a fire-resistant panel that can be used in variousapplications such as for materials for walls of subway stations,washrooms and kitchens, building interior or exterior materials forceilings and floors, floor of passenger cars, interior materials, andfor furniture, the fire-resistant panel having excellent fire-resistanceand a low dimensional change. The present invention also relates to afire-resistant decorative panel using the fire-resistant panel.

(b) Description of the Related Art

A common melamine-based decorative plate is generally formed by pressinga plurality of layers consisting of a surface protective layer and adecoration layer both impregnated by a melamine resin, and a core layerimpregnated by a phenol resin onto kraft paper, using a multi-stagepress at an elevated temperature under a high pressure. However, thesedecorative plates have drawbacks of being thermally weak due to theirhigh content of resins and pulp layers.

Therefore, in order to meet the requirement of fire-resistance formaterials used as building interior and exterior materials, furniture,and the like, ground stone or processed metals are used, andalternately, tiles made of ceramics or porcelain are attached to thesurface. Though these materials have good durability andfire-resistance, they have drawbacks of a high manufacturing cost, aheavy weight, and low workability; and furthermore there is limitationfor their use as colorful decoration.

In order to solve the above-mentioned problems, fire-resistantmelamine-based decorative materials comprising a specific inorganiccompound in their core-material layer have been proposed, examples ofwhich can be found in Japanese Patent Pub. Nos. 03-253342 (FIG. 1),11-268186 (FIG. 2), 10-305527 (FIGS. 2 and 3), 10-305525 (FIGS. 2 and3), etc.

These decorative panels have a multi-layered configuration consistingof, from top to bottom, a sheet for a decorative layer using a patternedsubstrate and a melamine resin, a basic material layer made by blendingan inorganic filler such as a nonwoven glass fabric and aluminumhydroxide with a melamine resin or a phenol resin and by impregnating orcoating, a reinforcing layer made by blending and impregnating anonwoven glass fabric with a melamine resin or a phenol resin, anotherbasic material layer and another decorative layer. These layers aremolded with a multi-stage press at a high temperature under a highpressure.

However, although such conventional fire-resistant melamine-baseddecorative panels exhibit improved fire-resistance compared with commonmelamine-based decorative panels, there are still problems in that theirfire-resistance and dimensional stability are insufficient because alarge amount of resin is used in order to improve strength andprocessability of the decorative panels and their manufacturing cost isincreased due to the use of inorganic filler such as aluminum hydroxide.

SUMMARY OF THE INVENTION

Taking into consideration of the problems of the prior arts, an objectof the present invention is to provide a fire-resistant panel havingexcellent fire-resistance and dimensional stability; and also to providea fire-resistant decorative panel using the same.

Another object of the present invention is to provide a fire-resistantpanel comprising an inorganic filler that is capable to impart superiorworkability upon the resin, and to provide a fire-resistant decorativepanel using the same.

Yet another object of the present invention is to provide afire-resistant panel comprising an inorganic filler that is capable toimpart superior strength, and to provide a fire-resistant decorativepanel using the same.

In order to achieve these objects and others, the present inventionprovides a fire-resistant panel comprising: a) a substrate material of awoven or nonwoven fabric of inorganic fiber, or a paper; and b) a resincompound containing the following materials which are impregnated orcoated onto the substrate material set forth in a): i) a thermosettingresin selected from the group consisting of a phenol resin, a modifiedphenol resin, a modified phenol-urea resin, a melamine resin, a modifiedmelamine resin, a modified melamine-urea resin, a urea resin, and amodified urea resin; and ii) loess.

Further, the present invention provides a fire-resistant decorativepanel comprising: a) a decoration layer formed by impregnating orcoating a thermosetting resin onto a patterned substrate; and b) acore-material layer formed by impregnating or coating a substratematerial of a woven or nonwoven fabric of inorganic fiber, or a paper,with a resin compound which contains an inorganic filler having loess asa main component and a thermosetting resin selected from the groupconsisting of a phenol resin, a modified phenol resin, a modifiedphenol-urea resin, a melamine resin, and a modified melamine resin, amodified melamine-urea resin, a urea resin, and a modified urea resin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a conventional fire-resistant decorativematerial.

FIG. 2 is a sectional view of a conventional fire-resistant decorativepanel.

FIG. 3 is a sectional view of another conventional fire-resistantdecorative panel.

FIG. 4 is a sectional view of a fire-resistant decorative panelaccording to the present invention, wherein loess is used.

FIG. 5 a sectional view of a fire-resistant decorative panel accordingto the present invention, wherein loess is used.

FIG. 6 a sectional view of a fire-resistant decorative panel accordingto the present invention, wherein loess is used.

Reference numbers are used such that 11 denotes decorative layer, 12denotes core-material layer, 13 denotes reinforcing layer, 21 denotesdecoration layer, 100 denotes fire-resistant decorative material, 200denotes fire-resistant decorative plate, and 300 denotes fire-resistantdecorative panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be explained more specifically in thefollowing.

The present invention provides an integrated fire-resistant panel formedby impregnating or coating on a substrate of woven or nonwoven fabricmade from an inorganic fiber such as glass fiber or alumina fiber, or apaper, with a resin compound including an inorganic filler having loessas a main component; a thermosetting resin selected from the groupconsisting of a phenol resin, a modified phenol resin, a modifiedphenol-urea resin, a melamine resin, a modified melamine resin, amodified melamine-urea resin, a urea resin, and a modified urea resin;and a good fire retardant.

The present invention also provides a fire-resistant decorative panelhaving a patterned substrate integrated by superposing and molding underhigh temperature and pressure on a surface and/or a rear face of alaminated sheet substrate having a plurality of these fire-resistantpanels that are used as substrate materials, the patterned sheet beingimpregnated with a thermosetting resin such as a melamine resin. Thedecorative panel may have a reinforcing layer interposed between thecore-material layer and the decoration layer, or between each of thecore-material layers, the reinforcing layer being formed by impregnatingor coating a woven fabric of inorganic fiber with a resin compound of amodified melamine resin or a modified phenol resin.

The core-material layer and the reinforcing layer may be used in singleor multiple layers, the configuration of which can be varied accordingto the application and thickness thereof. Particularly, if they are usedas a wall body, they are preferably prepared to have a thickness of 2 to5 mm, and in this case the number of core-material layers may be 3 to100 sheets and the number of reinforcing layers may be 1 to 20 sheetsdepending on the necessity.

When the fire-resistant panel is formed into a fire-resistant decorativepanel, it may be subjected to various methods of decoration.

The decoration methods include, as typical examples, coating the surfaceof the fire-resistant panel with paint and the like, and impregnating orcoating the decoration layer with a thermosetting resin and the like asdescribed above and then attached the treated layer to the surface ofthe fire-resistant panel. The decorative panel may be specifically nameda melamine decorative panel, a phenol decorative panel, an acryl-baseddecorative panel, or a urethane-based decorative panel in accordancewith the kind of resin contained in the finish coat applied or the kindof thermosetting resin impregnated in the decoration layer such asmelamine resin, phenol resin, acryl resin, or urethane resin.

A decorative panel more suitable for use of a fire-resistant panel ofthe present invention, considering that the fire-resistant panel uses athermosetting resin, is made by superposing a decoration layerimpregnated or coated with a thermosetting resin and the like on thesurface of a patterned paper, and then heat-pressing to effectattachment.

The types of decorative panels according to the invention are describedin the following.

As a first type, a fire-resistant decorative panel using loesscomprises, from top to bottom: i) a decoration layer; and ii) aplurality of core-material layers.

As a second type, a fire-resistant decorative panel using loesscomprises, from top to bottom (FIG. 5): i) a decoration layer; ii) aplurality of core-material layers; and iii) a decoration layer.

As a third type, a fire-resistant decorative panel using loesscomprises, from top to bottom (FIG. 4): i) a decoration layer; ii) aplurality of core-material layers; iii) a reinforcing layer; iv) aplurality of core-material layers; and v) a decoration layer.

As a fourth type, a fire-resistant decorative panel using loesscomprises, from top to bottom (FIG. 6): i) a decoration layer; ii) areinforcing layer; iii) a plurality of core-material layers; iv) areinforcing layer; and v) a decoration layer.

In addition of the above types, a fire-resistant decorative panelaccording to the present invention can be prepared by means of variousconfiguration of layers, and it is not to be limited to the above types.

In the following, the above layers are explained, respectively.

The core-material layer of a fire-resistant panel or a fire-resistantdecorative panel according to the present invention is a sheet shapedlayer formed by impregnating or coating a substrate material of a wovenor nonwoven fabric of inorganic fiber or a paper, with a resin compoundwhich contains an inorganic filler having loess as a main component anda thermosetting resin selected from a group consisting of a phenolresin, a modified phenol resin, a modified phenol-urea resin, a melamineresin, a modified melamine resin, a modified melamine-urea resin, a urearesin, and a modified urea resin.

The substrate material for the core-material layer is preferably a wovenor nonwoven fabric of inorganic fibers such as glass fiber or aluminafiber, or a paper such as kraft paper. Particularly, a preferredsubstrate material is a nonwoven fabric of glass fiber that is made bychopping a glass fiber having a composition of E-glass with a fiberdiameter of 6 to 30 gim into a length of 10. to 50 mm using a needlingmachine, and then by blending a binder such as an epoxy resin, an acrylresin, or a polyvinyl alcohol resin therein.

The substrate material preferably has weight per unit area of 30 to 200g/Ill2. When the weight per unit area is less than 30 g/lil2, problemsmay be caused during impregnating, coating, forming or handling due toinsufficient strength of the decorative panel made. On the other hand,when the weight per unit area exceeds 200 g/lll2, the panel becomes hardand efficiency of impregnation or coating as well as workability, istowered.

It is preferred that the resin compound of modified melamine resin ormodified phenol resin impregnated into the substrate material for thecore-material layer comprises: i) 3.0% to 10.0% by weight (based onsolid mass) of a first condensate of melamine or phenol resin; ii) 50%to 80% by weight of loess; iii) 1.0% to 5.0% by weight of fireretardant; and iv) 10% to 40% by weight of solvent (water or alcohol).

Specifically, when the compound contains not more than 5% by weight ofthe modified melamine resin or modified phenol resin and more than 4.0%by weight of the fire retardant, it can be classified as Grade 1 for afire-resistance test according to Korean Standard No. KS F 2271 entitled“Testing method for incombustibility of internal finish materials andelements of building.” In the resin compound, a part of the loess to beused as an inorganic filler may be replaced by aluminum hydroxide,magnesium hydroxide, talc, or the like in order to improve workabilityafter the process of press-forming.

In such a case, the composition of the resin compound comprises: i) 3.0%to 10.0% by weight (based on solid mass) of a first condensate ofmelamine or phenol resin; ii) 40% to 70% by weight of loess; iii) 3% to20% by weight of an alternative inorganic filler such as aluminumhydroxide, magnesium hydroxide or talc; iv) 1.0% to 5.0% by weight offire retardant; and v) 10% to 40% by weight of solvent (water oralcohol).

The resin compound may be used as it is or with the addition of adiluent such as water or alcohol. The amount of the resin compound to beimpregnated (or coated) is preferably 400 to 2000 parts by weight basedon 100 parts by weight of the substrate material. If the impregnatedamount is less than 400 parts by weight, more sheets are required toadjust the specified thickness and the cost will be increased, whereasif the amount exceeds 2000 parts by weight, drying time is extended tothereby lower the productivity, and inter-layer adhesive strength afterpress-forming may also become weak.

The modified melamine resin and modified phenol resin are liquid-phaseresins, and they are the first condensates prepared by a usualpolymerization process using 25% to 45% by weight of melamine or phenol,30% to 60% by weight of formaldehyde, 2% to 5% by weight of aplasticizer and 10% to 25% by weight of distilled water as a solvent. Inthe case of using the melamine resin, a curing agent may be furtheradded in order to reduce the time required for curing.

As the fire retardant, a liquid phase fire retardant containing phosphorand nitrogen and a solid phase fire retardant, dicyandiamide, may beused in combination. The charging method is preferably carried out byadding 100 parts by weight of the first condensate, 15 to 30 parts byweight of fire retardant containing phosphor/nitrogen, and 5 to 10 partsby weight of dicyandiamide as a solid phase fire retardant. By means ofaddition of these fire retardants, the resin will acquire fire-resistantproperties.

A preferable example of the liquid phase fire retardant containingphosphor and nitrogen is Melflam 131 A (product of SKW Trostberg,Germany), which is an aqueous solution containing nitrogen and phosphorand which contains 35% to 45% by weight of active components. A functionof this fire retardant is to produce polymerized polyphosphoric acid bypromoting thermal polycondensation of polyphosphoric acid if thedecorative panel is subjected to a high temperature when a fire breaksout, and the thus-produced polymeric polyphosphoric acid will then actas a dehydrogenation catalyst to form charcoal, and thereby oxygen andheat will be interrupted and superior nonflammable effects are thenceexhibited.

Further, many kinds of nitrogen components contained in the melamineresin also assist in the production of polymeric polyphosphoric acid.

When such a liquid phase fire retardant containing phosphor and nitrogenis used together with dicyandiamide as a solid phase fire retardant, theeffect will be doubled by virtue of fire-resistant synergism.

Dicyandiamide is a solid and it reacts with various materials containedin the resin compound such as formaldehyde, water, and ammonium salt tochange them into a nonflammable substance, thereby resulting infire-resistant effects that exclude the ability of the decorative panelto burn if it is subjected to a high temperature when a fire breaks out.

Particularly, when it is used together with a liquid phase fireretardant containing phosphor and nitrogen, the effect will be doubledby virtue of fire-resistant synergism as previously noted.

Loess as an inorganic filler does not transfer heat if the decorativepanel is subjected to a high temperature when a fire breaks out, andadditionally the water of crystallization contained within the loesscomponent absorbs heat to provide a fire-resistant effect. Furthermore,loess effects a uniform heat transfer to the resin during the formationof the decorative panel under a condition of high temperature and highpressure, and it provides good adhesion between each layer.

In general, loess is known to have pharmaceutical efficacy such asdetoxifying potential or antibacterial effects, and it is widely used asa purifying agent against environmental pollutants, for cosmeticmaterials and as therapeutics for folk remedies. As loess has acapability of infrared irradiation in addition to its conventional uses,it can provide a warming effect to the human body as well as thermalinsulation to buildings when it is included within the decoration panelaccording to the present invention.

Loess used in the present invention exhibits different colors such aswhite, yellow or red depending on the district of its origin, and it isfound in Korea at Sancheong in Gyeongsangnam-do, Chongdo inGyeongsangbuk-do, Gurye or Hwasun in Jeollanam-do and Buan inJeollabuk-do is particularly preferred. Preferably, the loess has acomposition of 10% to 90% by weight of silicon dioxide, 10% to 80% byweight of aluminum oxide, 0.1% to 50% by weight of iron oxide, 0.1% to30% by weight of magnesium oxide, 0.1% to 50% by weight of calciumoxide, 0.1% to 30% by weight of potassium oxide, 0.1% to 5% by weight ofmineral oxide and inorganic material, 0% to 5% by weight of moisture and0.1% to 20% by weight of impurities as a remainder.

Loess used in the present invention may be natural loess itself or acalcined loess which has been treated by calcining at a temperature of300° to 1000° C. Such calcined loess is obtained by eliminating organiccompounds contained therein and then by reducing irregularly scatteredmicropores as well as water of crystallization to a certain level. Suchcalcined loess can be used in further increased quantities because ithas a reduced amount of oil absorption during blending with resin, thusproviding better fire-resistant properties.

The particle size distribution of loess used as an inorganic filler inthe present invention is preferably 5 to 300/ml while its mean particlesize is preferably 10 to 50 fini. If loess with particle size below theabove range is used, the viscosity of the resin will become high due tostrong oil absorptivity of resin and solvent so that efficiency ofimpregnation or coating workability is lowered. On the other hand, ifloess with a particle size of over the above range is used, smoothnessof the panel surface may be reduced by the presence of large particleson the surface during the formation of the decorative panel under acondition of high temperature and high pressure after impregnation orcoating.

The particle size of the alternative inorganic filler such as aluminumhydroxide, magnesium hydroxide or talc which is used to replace a partof the loess is preferably in the range of 10 to 50; nl. If an inorganicfiller with a particle size below the above range is used, the resinviscosity will become high due to strong oil absorptivity of resin andsolvent so that workability is lowered. On the other hand, if aninorganic filler with a particle size of over the above range is used,smoothness of panel surface may be reduced by the presence of largeparticles on the surface after the product is formed.

The decorative panel according to the present invention can be made tohave a reinforcing layer interposed between the core-material layer andthe decoration layer, or between each core-material layers, wherein thereinforcing layer is formed by impregnating or coating a woven ornonwoven fabric of inorganic fiber such as glass fiber and aluminafiber, or kraft paper with modified melamine resin or modified phenolresin. The woven fabric of inorganic fiber used as a substrate materialfor the reinforcing layer is preferably a woven fabric of glass fiberhaving an E-glass composition, made by means of a weaving machine.

In the case the substrate material of the reinforcing layer is wovenfabric, its weight per unit area is preferably in the range of 30 to 150g/1ll2.

If the weight per unit area is less than 30 g/lil2, the thickness of thefiber will not be sufficient such that it will be too pliable and itshandling and workability during lamination will be poor. On the otherhand, if the weight per unit area is more than 150 g/m2, the fiber willbecome too thick such that marks of the fibers may be transcribed to thesurface of the panel upon production, and the adhesive strength willbecome too weak such that separation of the layers may occur. In thecase the substrate material of the reinforcing layer is kraft paper, itsweight per unit area is preferably 70 to 300 g/m2. If the weight perunit area is less than 70 g/l112, workability such as impregnation andlamination will become worse, and on the other hand, if the weight perunit area is more than 300 g/m2, it will be difficult to adjustthickness required in the panel production and the adhesive strengthbetween upper and lower layers will become too weak such that separationof the layers may occur.

The reinforcing layer is prepared by impregnating (or coating) 100 partsby weight of a woven fabric of inorganic fiber or kraft paper with 50 to500 parts by weight of the compound of modified melamine resin ormodified phenol resin which is used in the core-material layer.

Alternatively, impregnation can be carried out with 50 to 200 parts byweight of modified melamine resin alone or modified phenol resin alone,both containing no inorganic loess filler. However, the greater theamount of resin used, the worse the fire-resistance will be.

The decoration layer used for a surface and a rear face of themelamine-based decorative panel according to the present invention has asheet shape, and it comprises a thermosetting resin sheet made byimpregnating or coating 100 parts by weight of a paper substrate havinga weight per unit area of 40 to 200 g/1112. The substrate is made ofsynthetic pulp, wood, textile fabrics, organic synthetic fiber and thelike with 50 to 200 parts by weight of a resin such as melamine resin,phenol resin, acryl resin and urethane resin. When an inorganiccomponent such as titanium oxide is blended in the substrate material ofthe decoration layer, fire-resistance may be enhanced, and using alesser amount of resin is advantageous for fire-resistance.

The sheets for core-material layers and reinforcing layers produced asdescribed above are used in a plural numbers in consideration of panelthickness, with a single sheet of the decoration layer being used forthe surface and the rear face, respectively. These sheets are heated andpressed in a multi-stage press, and thereby a fire-resistant decorativepanel comprising loess according to the present invention is produced.In order to impart an embossing effect to the surface, a mirror plate,embossed plate, or the like may be superposed on the product surfaceduring forming, and a protective film may be attached after forming toprevent the surface of the product from being scratched.

The fire-resistant decorative panel according to the present inventionis designed for attachment in such a manner that the decoration layer isoriented to face outward in order to enable the decorative surface to beseen from outside.

The fire-resistant decorative panel according to the present inventionitself can be attached to cement walls, steel plates, wood and the likeby means of an adhesive, etc. Since the fire-resistant decorative panelof the invention exhibits a low dimensional change, deformation is notcaused even when a rear substrate such as a polyvinyl chloride (PVC)sheet, plywood, a medium density fiber board (MDF), and a high densityfiber board (HDF) is separately attached to its rear face, depending onits usage.

As the fire-resistant decorative panel has excellent fire-resistance anda low dimensional change, it is a suitable for walls of subway stations,washrooms and kitchens, building interior or exterior materials forceilings and floors, floor of passenger cars, interior materials, andfor furniture.

The present invention will be described in further detail with referenceto the following examples and comparative examples. However, theexamples are intended to be illustrative of the present invention, andthe present invention is not to be limited to them.

EXAMPLES Example 1

(Preparation of a compound of a fire-resistant melamine resin and loessfor a core-material layer and a reinforcing layer) 1. 7 mol offormaldehyde was added to 1 mol of melamine and the mixture was reactedat 95° C. under a weak alkaline condition, and then the content of thereagents was controlled by adding a plasticizer and water to obtain aninitial condensation product. 0.1 parts by weight of paratoluenesulfonicacid (PTSA) as a hardener and 0.1 parts by weight of Melpers RH4(product of SKW Trostberg, Germany) as a potential hardener were addedto 100 parts by weight of this initial condensation product to obtain amelamine resin. 20 parts by weight of Melflam 131A as a liquid fireretardant and 4.0 parts by weight of dicyandiamide as a solid fireretardant were added to 100 parts by weight of the melamine resin toobtain a fire-resistant melamine resin.

900 parts by weight of loess having an average particle size of 10 to 50pu were added to 100 parts by weight of the above-obtainedfire-resistant melamine resin to prepare a resin compound offire-resistant melamine resin and loess.

(Preparation of a core-material layer sheet) Nonwoven fabric of E-glassfiber with a weight per unit area of 110 g/1×12 obtained by treatment ofthe above resin compound of fire-resistant melamine resin and loess withacryl resin-based binder was impregnated and it was dried to prepare acore-material layer sheet having a degree of impregnation of 800% byweight based on dry weight.

(Preparation of a reinforcing layer sheet) Nonwoven fabric of E-glassfiber with a weight per unit area of 60 g/m' was impregnated with theabove compound of fire-resistant melamine resin and loess, and it wasdried to prepare a reinforcing layer sheet of 300% by weight based ondry weight.

(Preparation of a melamine resin for decoration layer) 1.7 mol offormaldehyde was added to 1 mol of melamine and the mixture was reactedat 95° C. under a weak alkaline condition, and then the content of thereagents was controlled by adding water to obtain an initialcondensation product. 0.2 parts by weight of paratoluenesulfonic acid(PTSA) as a hardener and 0.2 parts by weight of Melpers RH4 (product ofSKW Trostberg, Germany) as a potential hardener (a hardener whichpromotes reaction exclusively at a high temperature) were added to 100parts by weight of this initial condensation product to prepare amelamine resin.

(Preparation of a decoration layer sheet) The above-obtained melamineresin was impregnated to 90% by weight into printed patterned paper of80/111' into which titanic oxide was incorporated, and a decorationlayer sheet was obtained.

(Preparation of a fire-resistant melamine decorative panel: FIG. 4) Theabove-obtained sheets were stacked from top to bottom in the order of 1sheet of the decoration layer, 3 sheets of the core-material layersheet, 1 sheet of the reinforcing layer sheet, 3 sheets of thecore-material layer sheet, and 1 sheet of the decoration layer, and thena mirror plate of stainless steel was superposed on both sides. It wasall subjected to heat-pressing at a temperture of 150° C. and a pressureof 100 kgf/cuf for 30 minutes, and thus a fire-resistant melaminedecorative panel having a thickness of 3 mm was prepared.

Example 2

(Preparation of a compound of a fire-resistant phenol resin and loessfor a core-material layer) 1.4 mol of formaldehyde was added to 1 mol ofphenol and the mixture was reacted at 100° C. under a weak alkalinecondition, and then the content of the reagents was controlled by addingwater to obtain an initial condensation product. 20 parts by weight ofMelflam 131 A as a liquid fire retardant and 4.0 parts by weight ofdicyandiamide as a solid fire retardant were added to 100 parts byweight of this initial condensation product to obtain a fire-resistantphenol resin.

900 parts by weight of loess having an average particle size of 10 to 50filn was added to 100 parts by weight of the above-obtainedfire-resistant phenol resin to prepare a compound of fire-resistantphenol resin and loess.

(Preparation of a core-material layer sheet) Nonwoven fabric of E-glassfiber with a weight per unit area of 110 g/m2 obtained by treatment withacryl resin-based binder was impregnated with the above compound offire-resistant phenol resin and loess, and it was dried to prepare acore-material layer sheet having a degree of impregnation of 800% byweight based on dry weight.

(Preparation of a decoration layer sheet) A decoration layer sheet as inExample 1 was prepared.

(Preparation of a fire-resistant melamine decorative panel: FIG. 5) Theabove-obtained sheets were stacked from top to bottom in the order of 1sheet of the decoration layer, 6 sheets of the core-material layersheet, and 1 sheet of the decoration layer, and then a mirror plate ofstainless steel was superposed on both sides. It was all subjected toheat-pressing at a temperture of 150° C. and a pressure of 100 kgf/cill2for 30 minutes, and thus a fire-resistant melamine decorative panelhaving a thickness of 3 mm was prepared.

Example 3

(Preparation of a core-material layer sheet) A core-material layer sheetas in Example 1 was prepared.

(Preparation of a reinforcing layer sheet) A reinforcing layer sheet asin Example 1 was prepared.

(Preparation of a decoration layer sheet) A decoration layer sheet as inExample 1 was prepared.

(Preparation of a fire-resistant melamine decorative panel: FIG. 4) Theabove-obtained sheets were stacked from top to bottom in the order of 1sheet of the decoration layer, 1 sheet of the reinforcing layer sheet, 5sheets of the core-material layer sheet, 1 sheet of the reinforcinglayer sheet, and 1 sheet of the decoration layer, and then a mirrorplate of stainless steel was superposed on both sides. It was allsubjected to heat-pressing at a temperture of 150° C. and a pressure of100 kgf/cf for 30 minutes, and thus a fire-resistant melamine decorativepanel having a thickness of 3 mm was prepared.

Example 4

(Preparation of a compound of a fire-resistant phenol resin and loessfor a core-material layer) A fire-resistant phenol resin as in Example 2was prepared.

700 parts by weight of loess having an average particle size of 10 to 50u and 200 parts by weight of aluminum hydroxide having an averageparticle size of 10 to 50 tini were added to 100 parts by weight of theabove-obtained fire-resistant phenol resin and then mixed to prepare acompound of fire-resistant phenol resin, loess, and aluminum hydroxide.

(Preparation of a core-material layer sheet) Nonwoven fabric of E-glassfiber with a weight per unit area of 110 g/m' obtained by treatment withacryl resin-based binder was impregnated with the above compound offire-resistant phenol resin, loess, and aluminum hydroxide and it wasdried to prepare a core-material layer sheet having a degree ofimpregnation of 800% by weight based on dry weight.

(Preparation of a decoration layer sheet) A decoration layer sheet as inExample 1 was prepared.

(Preparation of a fire-resistant melamine decorative panel: FIG. 5) Theabove-obtained sheets were stacked from top to bottom in the order of 1sheet of the decoration layer, 6 sheets of the core-material layersheet, and 1 sheet of the decoration layer, and then a mirror plate ofstainless steel was superposed on both sides. It was all subjected toheat-pressing at a temperture of 150° C. and a pressure of 100 kgf/cill2for 30 minutes, and thus a fire-resistant melamine decorative panelhaving a thickness of 3 mm was prepared.

Example 5

(Preparation of a core-material layer sheet) A core-material layer sheetas in Example 1 was prepared.

(Preparation of a reinforcing layer (fire-resistant kraft layer) sheet)A fire-resistant kraft paper was impregnated to a weight per unit areaof 300 g/iu' with the fire-resistant phenol resin prepared in Example 2and dried to prepare a fire-resistant kraft layer sheet as a reinforcinglayer sheet of 80% by weight based on dry weight.

(Preparation of a decoration layer sheet) A decoration layer sheet as inExample 1 was prepared.

(Preparation of a fire-resistant decorative composite panel: FIG. 6) Theabove-obtained. sheets were stacked from top to bottom in the order of 1sheet of the decoration layer, 3 sheets of the core-material layersheet, 1 sheet of the reinforcing layer (fire-resistant kraft layer)sheet, 3 sheets of the core-material layer sheet, and 1 sheet of thedecoration layer, and then a mirror plate of stainless steel wassuperposed on both sides.

The stacked sheets were then subjected to heat-pressing at a temperatureof 150° C. and a pressure of 100 kgf/cuf for 30 minutes, and thus afire-resistant decorative panel having a thickness of 4.5 mm wasprepared.

Comparative Example 1

(Preparation of a core-material layer sheet) A core-material layer sheetwas prepared in the same manner as in Example 1 except that aluminumhydroxide having a particle size of 10 to 50 11111 was used instead ofloess as an inorganic filler.

(Preparation of a reinforcing layer sheet) A reinforcing layer sheet wasprepared in the same manner as in Example 1 except that aluminumhydroxide having a particle size of 10 to 50; In was used instead ofloess as an inorganic filler.

(Preparation of a decoration layer sheet) A decoration layer sheet as inExample 1 was prepared.

(Preparation of a fire-resistant melamine decorative panel: FIG. 4) Inthe same manner as in Example 1, the above-obtained sheets were stackedfrom top to bottom in the order of 1 sheet of the decoration layer, 3sheets of the core-material layer sheet, 1 sheet of the reinforcinglayer sheet, 3 sheets of the core-material layer sheet, and 1 sheet ofthe decoration layer, and then a mirror plate of stainless steel wassuperposed on both sides. The stacked sheets were then subjected toheat-pressing at a temperature of 150° C. and a pressure of 100 kgf/cuifor 30 minutes, and thus a fire-resistant melamine decorative panelhaving a thickness of 3 mm was prepared.

The physical properties of each of the fire-resistant melaminedecorative panels prepared in Examples 1 to 4 and Comparative Examples 1were compared, and the results are summarized in the following Table 1.

Table 1 Example Example Example Example Example Comparative ExampleFire-Surface passed passed passed passed passed passed resistance testSubstrate passed passed passed passed passed not passed Test Dimensionalstability 1−0.07%−0.07%−0.06%−0.07%−0.06%−0.14% Dimensional stability2+0.15%+0.15%+0.14%+0.15%+0.04%+0.30% Thickness 3 mm 3 mm 3 mm 3 mm 4.5mm 3 mm In the above table, fire-resistance data represent results of atest carried out in accordance with “Testing method for incombustibilityof internal finish materials and elements of building” as set forth inKS F2271, and each of the dimensional stability data represents resultsof a test carried out according to “Testing method for laminatedthermosetting high-pressure decorative sheets” as set forth in JIS K6902.

The fire-resistant panel and the fire-resistant decorative panelprepared by using loess according to the present invention providesdecorated plates integrally formed with a compound of a melamine resin,a phenol resin, or a modified resin, which uses a porous sheet such as awoven or nonwoven fabric made of inorganic fibers such as glass oralumina fibers, or kraft paper, and loess as main inorganic fillers,with the addition of a fire retardant. Therefore, it can be used formaterials for building interiors or exteriors, material for interiors,furniture and floors, and almost no deformation is caused due to itsexcellent fire-resistance as well as superior dimensional stability.

1. A fire-resistant decorative panel comprising loess, the panel beingprepared by superposing from top to bottom: a) a decoration layer formedby impregnating or coating a patterned substrate with a thermosettingresin; and b) a plurality of core-material layers formed by impregnatingor coating a substrate material of a woven or nonwoven fabric ofinorganic fiber, or a paper, with a resin compound which contains aninorganic filler having loess as a main component and a thermosettingresin selected from the group consisting of a phenol resin, a modifiedphenol resin, a modified phenol-urea resin, a melamine resin, a modifiedmelamine resin, a modified melamine-urea resin, a urea resin, and amodified urea resin, and then by forming it to be integrated byheat-pressing.
 2. A fire-resistant decorative panel comprising loess,the panel being prepared by superposing from top to bottom: a) adecoration layer formed by impregnating or coating a patterned substratewith a thermosetting resin; b) a plurality of core-material layersformed by impregnating or coating a substrate material of a woven ornonwoven fabric of inorganic fiber, or a paper, with a resin compoundwhich contains an inorganic filler having loess as a main component anda thermosetting resin selected from the group consisting of a phenolresin, a modified phenol resin, a modified phenol-urea resin, a melamineresin, a modified melamine resin, a modified melamine-urea resin, a urearesin, and a modified urea resin; and c) a decoration layer formed byimpregnating or coating a patterned substrate with a thermosettingresin, and then by forming it to be integrated by heat-pressing.
 3. Afire-resistant decorative panel comprising loess, the panel beingprepared by superposing from top to bottom: a) a decoration layer formedby impregnating or coating a patterned substrate with a thermosettingresin; b) a plurality of core-material layers formed by impregnating orcoating a substrate material of a woven or nonwoven fabric of inorganicfiber, or a paper, with a resin compound which contains an inorganicfiller having loess as a main component and a thermosetting resinselected from the group consisting of a phenol resin, a modified phenolresin, a modified phenol-urea resin, a melamine resin, a modifiedmelamine resin, a modified melamine-urea resin, a urea resin, and amodified urea resin; c) a reinforcing layer formed by impregnating orcoating a woven inorganic fiber fabric or kraft paper with a resincompound of a modified melamine resin or a modified phenol resin; d) aplurality of core-material layers formed by impregnating or coating asubstrate material of a woven or nonwoven fabric of inorganic fiber, ora paper, with a resin compound which contains an inorganic filler havingloess as a main component and a thermosetting resin selected from thegroup consisting of a phenol resin, a modified phenol resin, a modifiedphenol-urea resin, a melamine resin, a modified melamine resin, amodified melamine-urea resin, a urea resin, and a modified urea resin;and e) a decoration layer formed by impregnating or coating a patternedsubstrate with a thermosetting resin, and then by forming it to beintegrated by heat-pressing.
 4. A fire-resistant decorative panelcomprising loess, the panel being prepared by superposing from top tobottom: a) a decoration layer formed by impregnating or coating apatterned substrate with a thermosetting resin; b) a reinforcing layerformed by impregnating or coating a woven inorganic fiber fabric orkraft paper with a resin compound of a modified melamine resin or amodified phenol resin; c) a plurality of core-material layers formed byimpregnating or coating a substrate material of a woven or nonwovenfabric of inorganic fiber, or a paper, with a resin compound whichcontains an inorganic filler having loess as a main component and athermosetting resin selected from the group consisting of a phenolresin, a modified phenol resin, a modified phenol-urea resin, a melamineresin, a modified melamine resin, a modified melamine-urea resin, a urearesin, and a modified urea resin; d) a reinforcing layer formed byimpregnating or coating a woven inorganic fiber fabric or kraft paperwith a resin compound of a modified melamine resin or a modified phenolresin; and e) a decoration layer formed by impregnating or coating apatterned substrate with a thermosetting resin, and then by forming itto be integrated by heat-pressing.